Lead-control mechanism for engines



NM)". 11 g 1924.

. 1,515,133 H. K. ADAMS LEAD CONTROL MECHANISM FOR ENGINES Filed MaV 25. l9"0 3 Sheets-Sheet l Nov. 11 K, 4

- -H. K. ADAMS LEAD CONTROL MECHANISM FOR ENGINES Filed May 25. 1920 I5 Sheets-Sheet 2 Nam M 19240 1515,133

H. K. ADAMS LEAD G ONTROL MECHANISM FOR ENGINES Filed May 25. 1920 I5 Sheets-Sheet 5 Patented New. ll, i924.

LEAD-CONTROL MECHANISM FOR ENGINES.

Application filed May 25,

To (all whom it may concern:

Be it known. that I, HENRY K. Anni/is, a citizen of the United States, residing at Nashville, in the county of Davidson and State of Tennessee, have invented certain new and useful Improvements in Lead-Control Mechanism for Engines; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

This invention relates to lead control devices for inside admission piston valve locomotive engines and has for its object to provide a means which will be comparatively inexpensive to manufacture and more efficient in action than those heretofore propose With these and other Ob ects in view the invention consists in the novel details of construction and combinations of parts more fully hereinafter disclosed and particularly pointed out in the claims.

Referring to the accompanying drawings forming a part of this specificationin which like numerals designate like parts in all the views,

Figure 1 is a diagrammatic partly sectional view of a well known form of valve gear with my invention applied thereto;

Figures 2, and 3 are views of a mod1fi ed form of actuating bar and connections with the radius bar;

Figure l, is a side elevational View partially broken away of a power means for changing the distance between the centers 8 and 6 of the radius and actuating bars respectively Figure 5, is a sectional view of the parts shown in Figure 4:;

Figure 6, is a view tuating bar,

Figure '2', is a sectional view taken on the line "l-7 of Figure 5 looking in the direction of'the arrows;

Figure 8,, is a plan view of the member 33 detached; and

Figure 9, is a view taken on the line 9-9 of Figure 4 looking in the direction of the arrows;

In order that the invention may be the more clearly understood, it is said: This invention may be regarded as an improvement over. the well known Walschaert valve gear, which as is also well known is not provided of the head of the ac- 1920. Serial, N0. 384,222.

with any means for regulating the port opening of the steam valve in accordance with the requirements of various engine speeds. In fact, practice proves that it enough lead is given the valve in a Walschaert gear to suit high enginespeeds, difiic-ulties are subsequently encountered when starting a heavy train, because the lead required for said high speeds will not permit the holding of the steam as longas it would be possible to hold it if no lead had been given the valve in the first place. In addition to this, it is well known that a preadmission of steam at slow speeds limits the starting capacity very materially.

By employing this invention, on the other hand, the lead is automatically controlled for difierent speeds, and the above objections are obviated, as will now be made clear.

Referring to the drawings, 1 indicates a steam cylinder; 2 a piston therein; 3 steam ports ;v 4 an inside admission piston valve controlling said ports; 5 a valve rod operating said valve 4:; 6 a pivotal pin or connection between said rod and an actuating bar or combination lever 7 8 a pivotal connection or pin between said combination lever 7 and the radius bar 28; and 9 represents a link pivoted at 10 on the fixed support or frame work 11. Said radius bar 28 is pivotally connected at 12 with the block 13, slidable in the slot 14E of the link 9, and near its end is provided with the sleeve 15 piv0tally connected at 16 with one arm 17 of a bell crank lever 18- pivoted at 19 to said frame 11. 20 represents a pivotal connection between the bell crank 18 and the operating member 21 capable of being moved from the cab (not shown) of the locomotive.

From what has been said it will be clear that the reciprocation of the connection 2.1. will raise and lower the block 18 and pivot 12 in the slot 14 of the link 9, and that as the latter oscillates on its pivot 10 it will through the radius bar 28 and associated parts impart motion to the valve rod 5 and valve 4. Said link 9 is oscillated as iol lows: 22 represents one of the driving axles, 23 a crank turning with said axle, and the dotted line 24: represents a connection or eccentric rod between said crank and the end 25 of the link 9.

In the lValschaert type of valve gear illustrated prior to my invention, no means had been provided, so far as I am aware, for changing the lead of an inside admission piston valve while the engine is running. By my invention, on the other hand, it is merely necessary to change or vary the distance between the pivotal centers 6 and 8 in order to change said lead. For this purpose, in this invention there is provided the frame 26, which carries the ways or guides 27 see Figures 1, 5 and 7. The head of said lap and lead lever or actuating bar 7 is flattened as shown at 29, and is provided with a slot 30 in which slides the block 31 carrying the pivot or pin 8 to which said radius bar 28 is connected. Said pin 8 is reduced at its ends as best shown in Figure 5, and it fits the depending ears 32 of the member 33, Figures 5 and 8, slidable on the guide members 34, reciprocating in the said ways or guides 27.

It will therefore be clear from Figures 4, and 7 that as the member 34 reciprocates in the ways 27 itraises and lowers the pin 8 in a vertical plane, and that as the radius bar 28 reciprocates it moves said pin in a horizontal plane by virtue of the member 33 being slidable on the member 34. This last named motion is at right angles to said first named movements, as will be clear from Figure 5.

Rigid with said guide members 34 are the guide members 35, Figures 5 and 7, which are integral with the member 36, having the screw threaded hub member 37 adapted to receive the screw threaded end of the piston rod, or member 38, rigid with the piston 39 and passing through the stuffing box 40. 41 represents a cylinder in which the piston 39 reciprocates, and 42 and 43 represent air or steam pipes for supplying fluid under pressure to both sides of the piston 39. 44 represents a cap for covering the cylinder 41, and 45, Figure 1, a fluid supply pipe for feeding the pipes 42 and 43. 46 represents a valve controlling the pipes 42, 43 and 45, and 47 a connection between said valve and the bell crank lever 18 as shown.

It will now be clear that when the operating rod 21 is moved the connection 47 will turn the valve 46, thus admitting fluid under pressure to one side or the other of the piston 39, which through its piston rod 38 and associated parts, will move the block 31 in the slot 30, and thus vary the distance between the centers 6 and 8.

In the somewhat modified form of act-uating rod or lap and lead lever 7 shown in Figures 2 and 3, the head is flattened as at 50, and a sliding block member 51 fits over said head and has integral therewith the pivot pin 8 as shown.

The operation of this invention will be readily understood from the foregoing, but may be briefly summarized as follows:

lVhen it is desired to change the cut off of the valve 4, the engineer operates the bar 21,

which operates the bell crank 18 and the connection 47 to the valve 46. The arm 17 of the bell crank moves the pin 16, the radius bar, and the blocks 13 in the slot 14 of the link 9, while the said link is oscillated on its center 10 from the crank pin 23 and 0011- nection 24. The operation of the valve 46 controls the passage of fluid under pressure through the pipes 42 and 43, and the up or down movement of the piston 39, piston rod 38, block 31, and pin 8, thus changing or varying the distance between the centers of the pins 8 and 6, and therefore the lead of the valve 4.

As best shown in Figure 5, a screw having a head 61 passes down into the cylinder 41 and thus adjusts the upward movement of the piston. 39, and therefore the amount of lead that may be given the valve 4, when valve 46 is opened. As best shown in Figure- 6, the axis 65 of the slot 30 is not coincident with the axis 66 of the actuating bar or lap and lead lever 7, but makes a small angle of say 3 to 5 therewith.

Theoretically, the axis 65, as well as the sides of the slot 30, should be the arcs of circles struck from the center of radius bar pin 12 when the actuating bar 7 is in a substantially vertical position and the pin 12 coincides with the center of oscillation 10 of the link: 9, but in practice the radii of such arcs are so long, and the length of the slot 30 is so short relative thereto, that the sides of the said slot may be machined substantially as straight lines inclined to the axis of the bar 7 as shown, without in any way affecting the operation of the parts. This angularity of from 3' to 5 is to compensate for the fact that in practice the center of oscillation 10 of the link bar 9 must be placed in a horizontal plane lower than that passing through the center of the radius bar pin 8.

In other words, supposing the actuating bar 7 to be in a vertical position, with the pin 8 in its lowermost position in the slot 30, and the pivot 12 to coincide with the pivot 10, if the said pin is raised by the power means 39, as above described, it will carry with it the left hand end of the radius bar 28, as seen in Figure 1, the radius bar pivoting about the pin 12 and center 10, and the end carrying the pin 8 moving in an are about the said centers 1 0 and 12.

If it were always possible to position the link pivot 10 high enough or in the same horizontal plane as the pin 8, the axes 65 and 66 would coincide, for the actuating bar 7 in practice is disposed at right angles to the plane of the axles.

This disposition of parts possesses decided advantages involving a less port opening as is well known to those while it still permits the cross head member 33 to reciprocate in a straight line in the skilled in the art,

guide members 3 L, will be clear from the drawings.

It, will now be clear that in the well known alschaert gear the point 8 in Figure '1. is lined so that the distance between the points 8 and 6 is likewise fixed, and the control of the lead of the valve is constant, for any given setting. On the other hand, in this invention, the operation of the WValschaert gear is not disturbed at all, while the distance between the points 8 and 6 may be varied. Further, the Variation between these said points 8 and 6 being along a curve, having its center at the point 10, the position of the point 6 is not disturbed, while at the same time, a wider control 01 the lead of valve t is bad.

It is obvious that those skilled in the art may vary the details of construction as well as the arrangement of parts, without departing from the spirit of the invention, and therefore I do not wish to be limited to the above disclosure except as may be required by the claims.

lVhat I claim is:

1. In a VValschaert valve gear, the combination of a cylinder provided with ports; an inside admission piston valve having a stem controlling said ports; an actuating bar having a slot inclined to its axis pivotally connected to said stem; a continuous radius bar; a block in said slot havinga pivot to which said radius bar is connected; power means, a guide connected to said powor means; a connection between said guide and said pivot; means for adjusting one end of said radius bar; and connections by which the movements of said last named means controls said power means, substantially as described.

2. In a Valschaert valve gear, the combination of a cylinder provided with ports; a piston valve having a stem controlling said ports; an actuating bar having a slot and pivotally connected to said stem; a continuous radius bar; a block in said slot having a pivot with a reduced end for connection with said radius bar; power means comprising a piston, and a guide head having a connection with said reduced end for varying the distance between the connection of said radius and actuating bars; means for controlling the stroke of said piston; means for adjusting one end of said radius bar; and connections by which the movements of said last named means controls said power means, substantially as described.

3. In a- Nalchaert valve gear associated with a power means for controlling the lead of the engine valve the combination of an actuating bar; a valve stem; a pivotal connection between said stem and said bar; a continuous radius bar; a pivotal and slidable connection between said radius bar and said actuating bar; a piston; a guide head connected to said last named connection and to said piston; a cylinder provided with an adjustable stop in which said piston operates; and means comprising a valve to admit fluid under pressure to either sideof said piston at will for changing the distance between said actuating and radius bar connections, substantially as described.

at. In a lead control for VValschaert valve gears, the combination of an actuating bar having a slot; a pivot pin for a valve connection carried by said bar; a block in said slot; a continuous radius bar; a pivot pin connected to said radius bar carried by said block; a guiding cross head connected with the end of said last named pivot pin; and a power means comprising a piston connected to said cross head for moving said cross head and last named pin to and from said first named pin, substantially as described.

5. In a lead control for Nalschaert gears, the combination of an actuating bar having a slot inclined to the axis of said actuating bar; a pivot pin for a valve stem carried by said bar; a block in said slot; a continu ous radius bar; a pivot pin for said radius bar carried by said block; a cross head associated with said last named pivot pin; and a power means comprising a cylinder, piston and valve for varying the distance between said last named pin and said first named pin, substantially as described.

In testimony whereof I aiiix my signature.

HENRY K. ADAMS. 

